Levels of Processing, Encoding Specificity, Elaboration, and CHARM
Total Page:16
File Type:pdf, Size:1020Kb
Psychological Review VOLUME 92 NUMBER 1 JANUARY 1985 Levels of Processing, Encoding Specificity, Elaboration, and CHARM Janet Metcalfe Eich University of British Columbia, Vancouver, British Columbia, Canada A model of cued recall called CHARM (composite holographic associative recall model) is applied to several findings that have been investigated within the depth- of-processing framework. It is shown that, given some straightforward, empirically testable assumptions about the representations of the to-be-remembered items themselves, CHARM can account for the main effect of depth of processing, the problem of the negatives, encoding-specificity interactions, and effects—both facilitative and inhibitory—of elaboration. The CHARM model is extended to encompass some depth-of-processing effects found in recognition memory. One of the most interesting characteristics same in both cases, and so seems to be of human cognition is that when people attributable to the way a person processes process information, that processing is such and combines information. Although a large that the information may be changed or number of experiments have shown changes transformed. For instance, the verbal context due to context and it is generally agreed that in which a particular item is given is highly such biasing effects are fundamental to human influential in determining the interpretation cognition, our understanding of the processes of that item. If a word cat is presented in the underlying such interactive effects is far from context of lions, the feline qualities of the cat complete. are emphasized; whereas, if the same word The most interesting property of the mem- cat is presented in the context of dogs, the ory model called CHARM (composite holo- domesticated animal characteristics of the cat graphic associative recall model; Eich, 1982; are liable to be more salient. This result Metcalfe & Murdock, 1981; and see also occurs even though the stimulus may be the Borsellino & Poggio, 1973; Cavanagh, 1976; Gabor, 1968; Julesz & Pennington, 1965; Liepa, 1977; Longuet-Higgins, 1968; Mur- This research was facilitated by a Natural Sciences dock, 1982, 1983; van Heerden, 1963; Will- and Engineering Research Council (NSERC) postdoctoral fellowship, NSERC Grant A0505, and a University of shaw, 1981, for related models) is that the California, Los Angeles, intramural computing grant to operations for association formation, storage, the author. and retrieval in this model cause changes in I thank James Anderson, Robert Bjork, Patrick Cavan- the representation of items from input to agh, Fergus Craik, Eric Eich, Ronald Fisher, Thomas memory to output from memory. These Nelson, Anne Treisman, Endel Tulving, Thomas Wickens and four anonymous reviewers for their critiques and changes are sometimes just degradations of assistance. I thank Morris Moscovitch for providing data the initial input. Under some more interesting and materials relevant to Simulation 1, and Ronald conditions, though, the model causes system- Fisher for providing the materials as well as the design atic biasing. This biasing may affect the in- for Experiment 1. Requests for reprints should be sent to Janet Metcalfe terpretation of items as well as the level of Eich, Department of Psychology, University of Brit- recall. ish Columbia, Vancouver, British Columbia, Canada In the CHARM model, items are character- V6T 1Y7. ized as patterns of features. These patterns Copyright 1985 by the American Psychological Association, Inc. 0033-295X/85/S00.75 1 JANET METCALFE EICH may vary in their similarity to one another. of experiments that show the memorial con- The representations of items are associated sequences of varying the context in which by means of the operation of convolution items are presented have been conducted and stored in a composite memory trace in within the levels-of-processing framework which other associations are superimposed (Cermak & Craik, 1979; Craik & Lockhart, as well. In order to retrieve, the representation 1972). Within this framework, the context in of a cue item is correlated with the composite which an item is presented is often manipu- trace, resulting in a noisy and sometimes lated by giving subjects different orienting distorted item. This retrieved item may be tasks. For instance, a subject might be asked identified as a word—if the task is verbal— whether a target word rhymed with another by being matched to every item in a semantic word, or alternatively, whether a word was in lexicon. Figure 1 gives a schematic illustration a particular category. Such differences in of the CHARM model. The operations in the context result in pronounced effects on the boxes in the figure (i.e., convolution, addition, level of recall of targets. Another program of and correlation) are responsible for changes research (Thomson & Tulving, 1970; Tulving in the nature of the items that depend on & Osier, 1968; Tulving & Thomson, 1973) context. These operations are discussed in showed that it is not only the context at time more detail shortly. of study that is important, but also the context In this article I explore some of the me- at time of test. For instance, if a target item morial consequences of the changes in rep- CAT was encoded in the context of lions, but resentation—depending on context—that are is later probed with the cue dog, recall is predicted by the CHARM model. A number much poorer than if the initial context item FROM PERCEPTUAL ANALYSIS TO PATTERN IDENTIFICATION COMPOSITE MEMORY TRACE (ADD) Figure 1. A diagrammatic overview of CHARM. LEVELS AND CHARM is used. The nature of the elaborating context (shallowly). Many experiments have con- in which an item is presented also influences firmed that the manipulation of an orienting the recall of the item. Sometimes elaboration task produces a main effect on the goodness results in enhanced recall, and sometimes of recall or recognition. Of particular interest elaboration results in impaired recall. I pro- in this article are experiments that have pose that the memory processes in the CHARM produced not only a main effect of orienting model and the resultant changes in represen- task (i.e., level of processing), but also quali- tation are sufficient to account for many of fying interactions. The qualifying interactions the experimental results of levels of process- have given rise to a number of constructs ing, encoding specificity, and elaboration. such as elaboration (J. R. Anderson & Reder, Although I propose that many of the levels- 1979; Battig, 1979; Craik & Tulving, 1975; of-processing, test context, and elaboration Moscovitch & Craik, 1976; Ross, 1981), cue- effects are produced by the associative, stor- trace compatibility (Tulving, 1979; and see age, and retrieval mechanisms in CHARM, the also Bransford, Franks, Morris, & Stein, model was not originally designed with these 1979), and distinctiveness (Craik, 1979; Craik effects in mind. Rather the model was in- & Jacoby, 1979; Eysenck, 1979; Jacoby & tended to address the general question of how Craik, 1979; Klein & Saltz, 1976; Lockhart, it is that people associate ideas, store those Craik, & Jacoby, 1976; Nelson, 1979) that associations in memory, and then later, when have been evoked instead of or in addition given one idea, are able to retrieve another to the original depth hypothesis. However, as from memory. I have applied the model to a Jacoby and Dallas (1981) note, "Although wide range of human learning, memory, and there are currently a large number of exper- classification phenomena in the cued recall, iments showing effects of manipulating an or paired-associate paradigm (see Eich, 1982), orienting task, there is no generally accepted as well as to rehearsal and free recall of framework that incorporates the results of unrelated items (Metcalfe & Murdock, 1981). those experiments" (p. 309). In free recall, many effects appear to depend In none of the situations that are modeled on factors other than the mechanisms of using computer simulations of CHARM, do I association formation, storage, and retrieval. assume a priori that the initial encoding of For example, the availability of retrieval cues an item differs from one condition to another. due to the subject's state, and to primary To be more specific, I do not assume that (short-term) memory were important in the perceptual analysis produces different patterns holographic free-recall model, in a manner of features to represent the same word, CAT, similar to other free-recall models (J. R. for instance, before association formation Anderson, 1972; Atkinson & Shiffrin, 1968; and retrieval, depending on the experimental Gillund & Shiffrin, 1984; Raiijmakers & Shif- condition. Treisman (1979) reviewed the per- frin, 1981). Although of considerable interest ceptual literature that indicates that the re- and importance in their own right, these lation between perceptual operations and factors are nevertheless extraneous to the memory performance may not be as straight- transformational properties of composite hol- forward as was originally supposed. Jacoby ographic models that are of main interest and Dallas (1981) argued that if the levels here, so I mainly consider cued recall. Later manipulation has its effect by causing different in the article, I also sketch out how the main perceptual analyses—for instance, that a effect of depth of processing could be obtained shallow task results in the encoding of only in recognition, within the CHARM model. a few letters or phonemes, whereas